Actually, no. Ash's Pikachu was confirmed to be male in a Diamond and Pearl episode. Admittedly, he was already designed like a male Pikachu, but he was like that before Gen IV created those gender differences...

I don't think it's necessarily 'shipping' in this comic, I think it's more silly kid-stuff. Like when you're five and playing house and your next door neighbor declares you the dad, and herself the mommy. xD